The fire, which started around noon in grassland off Humboldt Road, east of Chico, burned through Stilson Canyon and over Doe Mill Ridge, into Butte Creek Canyon by late afternoon. The flames crossed Butte Creek, climbed out of the canyon and across the Skyway at Tuscan Ridge golf course.

The cause of the fire is under investigation.

Gov. Arnold Schwarzenegger has declared a state of emergency in Butte County due to the Humboldt and Ophir fires, which could result in more state firefighting equipment moved here.